1. Field
Example embodiments relate to transparent conductive thin films and electronic devices including the same.
2. Description of the Related Art
Electronic devices such as flat panel displays (e.g., a liquid crystal display and a light emitting diode display), touch screen panels, photovoltaic cells, and transparent transistors typically include transparent electrodes. Materials for the transparent electrode may be required to have a high transmittance of, for example, at least 80% and a low specific resistivity of, for example, 1×10−3 or lower. The currently available materials for the transparent electrode include indium tin oxide (ITO), tin oxide (SnO2), zinc oxide (ZnO), and the like. The ITO is an n-type semiconductor having an increased concentration of electrons due to the presence of SnO2. Electrical and optical characteristics of the ITO may depend on the electron concentration, the optical bandgap, the mobility of the electrons, and the like. The ITO may include a solid solution compound being composed of In2O3 at 90 wt % and SnO2 at 10 wt %, and may exhibit a high level of carrier concentration. However, the ITO tends to have poor flexibility, and limited reserves of indium may lead to an increasing cost thereof. As a result, an urgent need to develop a material that may substitute for the ITO remains. Tin oxides (e.g., SnO2) are less expensive than ITO and are chemically stable but may not be etched easily, their resistivity is higher than the resistivity of indium oxide and zinc oxide, and they may require a high processing temperature. Zinc oxide is reported to have a transmittance and an electrical conductivity that are comparable to the transmittance and the electrical conductivity of ITO, but it is chemically unstable and may not provide a high etching ratio and a well-defined pattern when it is subjected to a wet etching process. In particular, electronic devices such as OLEDs may require a transparent electrode being prepared by a vapor deposition at room temperature. However, most of the transparent electrodes deposited at room temperature tend to be amorphous or to have lower crystallinity, which may lead to a lower conductivity and a higher sheet resistance. Therefore, it is desirable to develop an electrode material that may show high transmittance and enhanced conductivity even when it is formed by deposition at room temperature.